Bovine Serum Albumin Treatment Research Articles

Influence of BSA Protein on Electrochemical Response of Genosensors

The bovine serum albumin (BSA) protein is employed in genosensors as nonspecific binding blocker. In this work, the influence of BSA on the electrochemical response of a DNA-based biosensor is explored by electrochemical impedance spectroscopy (EIS) and double pulse voltammetry technique. Each buffer component of the hybridization buffer is studied on bare gold electrodes and on single-stranded DNA (ssDNA)-functionalized electrodes. The BSA is found to have the higher influence on the sensor sensitivity. The superficial modification induced by BSA greatly affects the electrochemical signal due to steric hindrance, which decreases the device sensitivity. Thus, we propose a novel treatment method of the BSA by using the proteinase K. The proteinase K reduces the steric hindrance, improving the charge transfer at the electrode/solution interface and enhancing the genosensor sensitivity. The proposed method is based on a rapid BSA treatment. The BSA solution containing the proteinase K is kept for 1 h at 37 ° C to obtain BSA fragmentation and then heated up to 95 ° C for 2 min to inactivate the enzyme and denature the fragments. The method was tested successfully on a genosensor for the detection of the Campylobacter Jejuni. Double pulse current measurements clearly discriminate the presence of complementary DNA (cDNA) fragments with any other noncomplementary DNA (NcDNA) fragments.

Container material dictates stability of bacteriophage suspensions: Light scattering and infectivity measurements reveal mechanisms of infectious titre decay.

To measure the infectious titre (IT) decay rate for various bacteriophages as a function of storage container material. Additionally, parallel light scattering and infectious titre measurements reveal distinct mechanisms for IT loss, depending on phage. Suspensions of bacteriophages 44AHJD, P68 and gh-1 were stored in various labware. IT of each suspension was repeatedly measured over the course of 2 weeks. Large variability in IT decay was observed, with >4 log10 loss in glass and low-binding polypropylene. Incubation of polymer containers with Bovine Serum Albumin (BSA) resulted in a consistent reduction in IT decay. Aggregation state of phage suspensions was studied by nanoparticle tracking analysis (NTA), revealing highest aggregation in glass-stored suspensions and lowest after storage in BSA-treated containers. Glass and 'low-binding' containers may aggravate IT decay while BSA treatment may present an easy mitigation strategy. IT versus NTA titre diagrams highlight the importance of phage inactivation in combination with aggregation. Container material is a significant determinant of bacteriophage IT decay. It is therefore essential to confirm IT following storage and tailor choice of phage storage containers accordingly. Aggregation of phages and adsorption onto labware surfaces are not only the mechanisms accounting for IT loss but also biological instability.

Effects of Initially Adsorbed Proteins on Substrate Surfaces during Multilayer Heterogeneous Protein Adsorption

When multilayer heterogeneous proteins are adsorbed on substrate surfaces, the effects of the adsorption state of the initially adsorbed proteins may affect subsequent adsorption. In this study, the relationships between the adsorption state of the initially adsorbed proteins and the amount of secondary adsorbed proteins were examined. A carboxylate-terminated self-assembled monolayer was applied to bovine serum albumin (BSA) solutions of different concentrations for 180 min and subsequently applied to phosphate-buffered saline (PBS) for an additional 180 min to remove weakly adsorbed proteins. The amount of adsorbed proteins was measured using a quartz crystal microbalance with dissipation. The obtained BSA adsorption layer was then applied to mucin solution for 60 min. When a 1.7 mg/mL BSA solution was applied to the surface, the amount of adsorbed BSA after 10 min of adsorption and after washing with PBS for 167 min was >5 × 102 ng/cm2, representing the saturation amount of monolayer-adsorbed BSA in a side-on orientation. In contrast, the amount of adsorbed BSA after 10 min adsorption was <5 × 102 ng/cm2 when a BSA solution with a concentration <0.43 mg/mL was used. The velocity of BSA adsorption plateaued at approximately 0.43 mg/mL, suggesting that the orientation of the adsorbed protein was determined by protein treatment concentration immediately after the proteins were adsorbed. Furthermore, the amount of adsorbed mucin on the BSA adsorption layer decreased as initial BSA treatment concentration increased up to 0.43 mg/mL and plateaued at concentrations above 0.43 mg/mL. These results indicated that the orientation of the initially adsorbed protein was preserved for several hours and affected the subsequent adsorption of mucin.

CircZNF609 is involved in the pathogenesis of focal segmental glomerulosclerosis by sponging miR-615-5p

As a set of distinct syndromes, focal segmental glomerulosclerosis (FSGS) is the most common cause of adult nephrotic syndrome with diverse mechanisms. We recently found that expression of the circular RNA circZNF609 is increased in renal biopsies of lupus nephritis patients. In the present study, we aimed to determine whether circZNF609 participates in the pathogenesis of FSGS in mice given Adriamycin. In FSGS mice, circZNF609 was upregulated while miR-615-5p was downregulated in FSGS mice analyzed by qPCR and fluorescence in situ hybridization (FISH). Expression of podocyte proteins Wilms tumor 1 (WT1) and podocin were decreased, while expression of collagen 1 (COL1) and transforming growth factor-beta1 (TGF-β1) were increased on Western blotting. Renal circZNF609 levels were positively correlated and miR-615-5p levels were negatively correlated with the degree of podocyte injury and renal fibrosis. Importantly, circZNF609 and miR-615-5p co-localized to glomeruli and tubules on FISH. Perfect match seeds were found between circZNF609 and miR-615-5p and COL1 mRNA, leading us to explore mechanisms of circZNF609 in bovine serum albumin (BSA) stimulating HK-2 cells, which model the toxicity of proteinuria on tubular cells. In vitro studies, circZNF609 increased and miR-615-5p decreased after BSA treatment and were negatively correlated with each other. COL1 and TGF-β1 were both upregulated and negatively correlated with miR-615-5p. Lastly, circZNF609 expression increased in glomeruli and tubules of FSGS patient renal biopsies. We conclude that circZNF609 may play an important role in FSGS by sponging miR-615-5p.

Albumin promotes the progression of fibroblasts through late G1 into S-phase in the absence of growth factors

ABSTRACT G1 cell cycle progression is controlled largely by growth factors in early G1 indicating that it is appropriate to divide and by nutrients in late G1 indicating sufficient raw material for cell division. We previously mapped a late G1 cell cycle checkpoint for lipids upstream from a mammalian target of rapamycin complex 1 (mTORC1)-mediated checkpoint and downstream from a mid-G1 checkpoint known as the Restriction point. We therefore investigated a role for lipids in progression through late G1 into S-phase. Quiescent BJ-hTERT human fibroblasts were primed with 10% fetal bovine serum (FBS) for 3.5 h at which time, cells were treated with a mixture of lipids and carrier bovine serum albumin (BSA) along with [3 H]-thymidine deoxyribose ([3 H]-TdR) to monitor progression into S-phase. Surprisingly, BSA by itself was more effective than FBS in promoting progression to S-phase – the lipids had no impact on progression. While insulin strongly stimulated mTORC1 activity, it did not impact on [3 H]-TdR incorporation. Although BSA modestly elevated mTORC1 activity, rapamycin strongly inhibited BSA-induced progression to S-phase. BSA treatment promoted mitosis, but not progression through a second G1. Thus, after priming quiescent cells with FBS, albumin was sufficient to promote progression into S-phase. The BSA was not simply a source of amino acids in that amino acids were present in the culture media. We propose that the presence of albumin – the most abundant protein in serum – reflects a broader availability of essential amino acids needed for cell growth.

Advanced glycation end-products accelerate telomere attrition and increase pro-inflammatory mediators in human WIL2-NS cells.

This study investigated the effect of dietary sugars and advanced glycation end-products (AGE) on telomere dynamics in WIL2-NS cells. Dietary sugars [glucose (Glu) and fructose (Fru); 0.1 M each] were incubated with bovine serum albumin (BSA) (10 mg/ml) at 60 ± 1°C for 6 weeks to generate AGE-BSA. Liquid chromatography-mass spectrometry (LC-MS/MS) analysis showed total AGE levels as 87.74 ± 4.46 nmol/mg and 84.94 ± 4.28 nmol/mg respectively in Glu-BSA and Fru-BSA model. Cell treatment studies using WIL2-NS cells were based on either glucose, fructose (each 2.5-40 mM) or AGE-BSA (200-600 µg/ml) in a dose-dependent manner for 9 days. Telomere length (TL) was measured using qPCR. Nitric oxide (NO) production and tumour necrosis factor-α (TNF-α) levels were measured in WIL2-NS culture medium. An increasing trend for TNF-α and NO production was observed with higher concentration of glucose (R2 = 0.358; P = 0.019; R2 = 0.307; P = 0.027) and fructose (R2 = 0.669; P = 0.001; R2 = 0.339; P = 0.006). A decreasing trend for TL (R2 = 0.828; P = 0.000), and an increasing trend for NO production (R2 = 0.352; P = 0.031) were observed with increasing Glu-BSA concentrations. Fru-BSA treatment did not show significant trend on TL (R2 = 0.135; P = 0.352) with increasing concentration, however, a significant reduction was observed at 600 µg/ml (P < 0.01) when compared to BSA treatment. No trends for TNF-α levels and a decreasing trend on NO production (R2 = 0.5201; P = 0.019) was observed with increasing Fru-BSA treatment. In conclusion, this study demonstrates a potential relationship between dietary sugars, AGEs and telomere attrition. AGEs may also exert telomere shortening through the production of pro-inflammatory metabolites, which ultimately increase the risk of diabetes complications and age-related disease throughout lifespan.

Effect of Alpha-Linolenic Acid with Bovine Serum Albumin or Methyl-Beta-Cyclodextrin on Membrane Integrity and Oxidative Stress of Frozen-Thawed Boar Sperm.

The study was conducted to investigate the effects of alpha-linolenic acid (ALA) combined with bovine serum albumin (BSA) or methyl-beta-cyclodextrin (MBCD) on plasma and acrosomal membrane damages, mitochondrial activity, morphological abnormality, motility, and oxidative stress in frozen-thawed boar sperm. In previous our study, 3 ng/mL ALA had been shown protective effect during freezing process of boar sperm. Therefore, we used 3 ng/mL ALA in present study and ALA was combined with same molar ratio of BSA or MBCD (ALA+BSA and ALA+MBCD, respectively). To confirm the effect of two carrier proteins, same volume of BSA and MBCD without ALA were added during cryopreservation. Membrane damage, mitochondrial activity, reactive oxygen species (ROS) and lipid peroxidation (LPO) levels were measured using flow cytometry, and movement of sperm tail as motility parameter and morphological abnormality were observed under light microscope. In results, all of sperm parameters were enhanced by ALA combined with BSA or MBCD compared to control groups (p<0.05). Mitochondrial activity, morphological abnormality, ROS and LPO levels in ALA+BSA or MBCD groups were no significant difference compared with ALA, BSA and MBCD treatment groups. On the other hand, plasma and acrosomal membrane intact, and sperm motility in ALA+MBCD group were higher than single treatment groups (p<0.05), whereas ALA+BSA did not differ. Our findings indicate that carrier proteins such as BSA and MBCD could improve the effect of ALA during cryopreservation of boar sperm, and treatment of ALA with carrier proteins enhance membrane integrity, mitochondrial activity through reduction of ROS-induced LPO.

Effect of Bovine Serum Albumin on Red Blood Cell Optical Anisotropy Probed Through the Optomechanical Response in an Optical Trap

The dynamics of trapped entities in an Optical Trap (OT) can yield information with regards to their viscoelastic response as well as optical anisotropy, if any. Detailed analysis of such dynamics correlated with parameters which affect the response can yield additional clues to the exact effect of these on the trapped entities. In this work, we illustrate this point by showing how the altered behavior of Red Blood Cells (RBC) treated with Bovine Serum Albumin (BSA) yields information about the nature of action of BSA, on which there is no current consensus in literature. We conclude from our studies that BSA treatment leads to a change in the birefringence of the RBCs, a conclusion arrived at from the altered optomechanical response of such cells in a linearly polarized Gaussian beam OT. Furthermore, we argue that the observed changes in cellular optical anisotropy may be thought of as due to changes in the curvature of the RBC membrane. We also note that BSA action could help mimic pathological conditions that result in an altered cell shape.

Abstract P239: (Pro)Renin Receptor Contributes to Albumin Overload Nephropathy: Role of Site-1 Protease-Derived Soluble (Pro) Renin Receptor

(Pro) renin receptor (PRR) is a new member of the renin-angiotensin system (RAS) and its role in chronic kidney disease largely remains elusive. We tested the role of PRR in albumin overload (OA) nephropathy. Uninephretomized Sprague-Dawley rats were treated for 7 weeks with vehicle, bovine serum albumin (BSA) (5 g/kg/d via a single i.p. injection) or in combination with PRO20 (500 μg/kg/d via i.p. 3 times a day). The OA rat exhibited severe proteinuria (23-fold), interstitial fibrosis, and oxidative stress, accompanied with increases in urinary renin activity (3.6-fold), urinary angiotensinogen (AGT, 3.6-fold), urinary AngII(7.8-fold), renal ACE mRNA (2.4-fold), all of which were significantly attenuated by PRO20. Urinary soluble PRR (sPRR) as assessed by ELISA was increased 13.6-fold in the OA model. In cultured HK-2 cells, BSA treatment for 24 h decreased full-length PRR (76% reduction) and increased sPRR (8-fold). BSA also increased medium renin activity (3.0-fold), IL6 (2.9-fold for mRNA and 4.1-fold for medium protein) and IL8 (5.5-fold for mRNA and 2.6-fold for medium protein), all of which were attenuated by PRO20 or PRR siRNA. Although furin or ADAM19 was previously shown to mediate the generation of sPRR, inhibition of either one of these had no effect on BSA-induced cleavage of PRR. In contrast, a serine protease inhibitor AEBSF significantly suppressed the production of sPRR. Of serine proteases, proprotein convertases (PCs) mediates post-translational processing of proprotein to active protein and are of particular interest. Screening of 9 PCs led to the identification of site-1 protease (S1P) as the predominant cleavage enzyme. S1P inhibition with siRNA or PF-429242 reduced the sPRR production by 47% and 87%, respectively. PF-429242 also reduced renin activity by 40%, in parallel with suppressed IL6 and IL8 levels. Administration of a recombinant sPRR reversed all the effects of S1P inhibition. Mutagenesis of the S1P but not furin cleavage site in PRR blocked the cleavage. Together, these results suggest that PRR mediates OA-induced renal injury at least in part through S1P-derived sPRR.

Modifications of carbon black nanoparticle surfaces modulate type II pneumocyte homoeostasis

ABSTRACTInhalation uptake of carbon black nanoparticles (CBNP) bears the risk of morphological and functional lung impairment attributed to the highly reactive particle surface area. Chemical particle surface modifications might affect particle–cell interactions; however, thus far these alterations have not been determined. This is the first in vivo study comparing particle-induced acute lung injury using Printex®90 (Pr90, 7 µg), Printex®90 covered by benzo[a]pyrene or 9-nitroanthracene (BaP-Pr90, NA-Pr90, 7 µg, 15% BaP or NA by weight), and acetylene carbon black (CB) with polycyclic aromatic hydrocarbons (PAH-AB, 7 µg, 20% PAH by weight). All particles were suspended in distilled water with bovine serum albumin (BSA). In addition, the influence of suspension media was tested using Printex®90 suspended without BSA (Pr90−BSA, 7 µg). Quartz (DQ12, 7 µg), 70 µl saline (NaCl), and distilled water with or without BSA (H2O+/-BSA) were used as reference and controls. It was postulated that CBNP surface modifications trigger pulmonary responses. After oropharyngeal particle aspiration, lung functions were measured 2 d postexposure, followed by lung preparation for histological or bronchoalveolar lavage fluid (BALF) examinations and type II pneumocyte isolation on d 3. Head-out body plethysmography revealed reduced flow rates induced by PAH-AB. Examinations of BALF demonstrated reduced influx of macrophages after exposure to Pr90−BSA and decreased lymphocyte levels after Pr90+BSA or BaP-Pr90 treatment. Further, CBNP induced changes in mRNA expressions (surfactant proteins) in type II pneumocytes. These findings indicate that CBNP surface area and media modulate interactions between NP and lung cells in short-term experiments.

Integrating high electrical conductivity and photocatalytic activity in cotton fabric by cationizing for enriched coating of negatively charged graphene oxide

Electroconductive textiles have attended tremendous focus recently and researchers are making efforts to increase conductivity of e-textiles, in order to increase the use of such flexible and low cost textile materials. In this study, surface conductivity and photo catalytic activity of standard cotton fabric (SCF) was enhanced by modifying its surface charge, from negative to positive, using Bovine Serum Albumin (BSA) as a cationic agent, to convert it into cationised cotton fabric (CCF). Then, both types of fabrics were dip coated with a simple dip and dry technique for the adsorption of negatively charged graphene oxide (GO) sheets onto its surface. This resulted in 67.74% higher loading amount of GO on the CCF making self-assembly. Finally, this coating was chemically converted by vapor reduction using hydrazine hydrate to reduced graphene oxide (rGO) for restoration of a high electrical conductivity at the fabric surface. Our results revealed that with such high loading of GO, the surface resistance of CCF was only 40Ω/sq as compared to 510Ω/sq of the SCF and a 66% higher photo catalytic activity was also achieved through cationization for improved GO coating. Graphene coated SCF and CCF were characterized using FE-SEM, FTIR, Raman, UV–vis, WAXD, EDX and XPS spectroscopy to ascertain successful reduction of GO to rGO. The effect of BSA treatment on adsorption of cotton fabric was studied using drop shape analyzer to measure contact angle and for thermal and mechanical resistance, the fabric was tested for TGA and tensile strength, respectively. rGO coated fabric also showed slightly improved thermal stability yet a minor loss of strength was observed. The high flexibility, photocatalytic activity and excellent conductivity of this fabric suggests that it can be used as an electrode material for various applications.

The effect of nonenzymatic protein on lignocellulose enzymatic hydrolysis and simultaneous saccharification and fermentation.

Nonenzymatic protein was added to cellulase hydrolysis and simultaneous saccharification and fermentation (SSF) of different biomass materials. Adding bovine serum albumin (BSA) and corn steep before cellulase enhanced enzyme activity in solution and increased cellulose and xylose conversion rates. The cellulose conversion rate of filter paper hydrolysis was increased by 32.5 % with BSA treatment. When BSA was added before cellulase, the remaining activity in the solution was higher than that in a control without BSA pretreatment. During SSF with pretreated rice straw as the substrate, adding 1.0 mg/mL BSA increased the ethanol yield by 13.6 % and final xylose yield by 42.6 %. The results indicated that lignin interaction is not the only mechanism responsible for the positive BSA effect. BSA had a stabilizing effect on cellulase and relieved cumulative sugar inhibition of enzymatic hydrolysis of biomass materials. Thus, nonenzymatic protein addition represents a promising strategy in the biorefining of lignocellulose materials.

Bovine lactoferrin ingestion protects against inflammation via IL-11 induction in the small intestine of mice with hepatitis

Accumulating evidence suggests that orally ingested lactoferrin protects against inflammation. To assess the efficacy of orally administered bovine lactoferrin (bLF) against hepatitis and to identify the underlying mechanism, in the present study, we used four mouse models of hepatitis induced by d-galactosamine (GalN), carbon tetrachloride (CCl4), GalN plus lipopolysaccharide (LPS) and zymosan plus LPS. Intraperitoneal (i.p.) injection of GalN (500mg/kg body weight) in mice treated with bovine serum albumin (BSA) for 14d significantly increased serum aspartate aminotransferase (AST) concentrations compared with the untreated mice. However, orally administered bLF reduced AST concentrations compared with BSA treatment. In mice that received a single injection (0·4ml/kg) and twice-weekly injections (0·08ml/kg) of CCl4 for 24 weeks and pretreated with bLF for 14d and 24 weeks, respectively, significantly suppressed alanine aminotransferase and AST concentrations were observed compared with the BSA-treated control. Oral administration of bLF for 14d before i.p. injection of LPS (5mg/kg) plus GalN (1g/kg) significantly improved the survival rate. In mice that received intravenous injection of zymosan (25mg/kg) and LPS (15μg/kg) at 7d intervals, bLF reduced the elevation of AST concentrations and enhanced the production of IL-11 and bone morphogenetic protein 2 in the small intestine compared with the BSA-treated control. To evaluate the effects of IL-11, we used IL-11 receptor α-null mice treated with GalN, CCl4 and zymosan plus LPS. In this group, the activity of bLF was not significantly different from that of BSA. These data indicate that orally ingested bLF enhances the expression of IL-11 in the small intestine and up-regulates protective activity in mice with hepatitis.

Bovine Lactoferrin Promotes Corneal Wound Healing and Suppresses IL-1 Expression in Alkali Wounded Mouse Cornea

Purpose: Using an in vitro cell culture model, bovine lactoferrin (BLF) stimulates healing of alkali-induced human corneal epithelial wounds. The present study examined the efficacy of BLF in promoting healing of corneal injury in vivo and explored BLF modulation of interleukin-1 (IL-1) during wound healing.Methods: Alkali injury was induced to BALB/c mice by exposure of the mouse cornea to a sodium hydroxide (NaOH)-soaked filter disc for 2 min. The corneal surface was irrigated after the injury with saline. Topical BLF in phosphate buffered saline (PBS) (10 µl, 62.5 μM), bovine serum albumin (BSA) (10 µl, 62.5 μM in PBS) or PBS only (10 µl) were applied three times daily to both the alkali-injured and uninjured eyes for 3 d. Wound healing was assessed using 0.1% fluorescein staining under slit lamp microscope. The corneas at 6 h, 24 h or 3 d post-injury and treatment were excised and examined histologically, homogenized corneal tissue was evaluated for expression of IL-1α and IL-1β.Results: After 6 h post-wounding and treatment no significant reduction of wound area was observed between treatments and infiltrating cells or IL-1 expression were not elevated in any group. By 24 h, BLF-treatment resulted in accelerated wound closure (100%) compared to PBS and BSA treatment (70% and 65%, respectively). BLF treatment reduced infiltrating cells compared to controls and no elevation of IL-1, whereas controls displayed elevated infiltrating cells and increased levels of IL-1. After 3 d, mice treated with BLF exhibited complete wound closure while control corneas still exhibited some minor defects. Resolution of inflammation with minimal remaining infiltrating cells was observed in all corneas by day 3, coincident to normal levels of IL-1α and IL-1β.Conclusion: BLF accelerated healing of corneal alkali injury in BALB/c mice which was associated with suppression of IL-1 and reduced infiltrating cells.

Effect of Bovine Serum Albumin (BSA) on Enzymatic Cellulose Hydrolysis

Bovine serum albumin (BSA) was added to filter paper during the hydrolysis of cellulase. Adding BSA before the addition of the cellulase enhances enzyme activity in the solution, thereby increasing the conversion rate of cellulose. After 48 h of BSA treatment, the BSA adsorption quantities are 3.3, 4.6, 7.8, 17.2, and 28.3 mg/g substrate, each with different initial BSA concentration treatments at 50 °C; in addition, more cellulase was adsorbed onto the filter paper at 50 °C compared with 35 °C. After 48 h of hydrolysis, the free-enzyme activity could not be measured without the BSA treatment, whereas the remaining activity of the filter paper activity was approximately 41 % when treated with 1.0 mg/mL BSA. Even after 96 h of hydrolysis, 25 % still remained. Meanwhile, after 48 h of incubation without substrate, the remaining enzyme activities were increased 20.7 % (from 43.7 to 52.7 %) and 94.8 % (from 23.3 to 45.5 %) at 35 and 50 °C, respectively. Moreover, the effect of the BSA was more obvious at 35 °C compared with 50 °C. When using 15 filter paper cellulase units per gram substrate cellulase loading at 50 °C, the cellulose conversion was increased from 75 % (without BSA treatment) to ≥90 % when using BSA dosages between 0.1 and 1.5 mg/mL. Overall, these results suggest that there are promising strategies for BSA treatment in the reduction of enzyme requirements during the hydrolysis of cellulose.

Improved hydrophilicity, permeability, antifouling and mechanical performance of PVDF composite ultrafiltration membranes tailored by oxidized low-dimensional carbon nanomaterials

Polyvinylidene fluoride (PVDF)–oxidized carbon nanotubes (OMWCNTs), PVDF–graphene oxide (GO) and PVDF–OMWCNTs–GO composite ultrafiltration membranes were prepared by solution-blending the ternary mixture of PVDF–oxidized low-dimensional carbon nanomaterials–dimethylacetamide in combination with the phase inversion method. The microscope images of the PVDF matrix microstructure showed that the composite membranes exhibited a bigger mean pore size and higher roughness parameters than pristine membranes. The contact angle of the membranes decreased from 78.5° (PVDF) to 66.8° (PVDF–OMWCNTs), 66.4° (PVDF–GO) and 48.5° (PVDF–OMWCNTs–GO). For the PVDF–OMWCNTs, PVDF–GO and PVDF–OMWCNTs–GO composite membranes, there was a 99.33%, 173.03% and 240.03% increase in permeation flux and a 21.71%, 17.23% and 14.29% increase in bovine serum albumin (BSA) rejection, respectively, compared with those of the pristine membranes. The newly developed composite ultrafiltration membranes demonstrate an impressive prospect for the anti-irreversible fouling performance in multi-cycle operations from BSA treatment. Additionally, the addition of OMWCNTs and GO increased the tensile strength of composite membranes from 1.866 MPa to 2.106 MPa and 2.686 MPa, respectively. Conspicuously, the PVDF composite ultrafiltration membranes endowed with oxidized low-dimensional carbon nanomaterials demonstrated fascinating hydrophilicity, permeability, antifouling and mechanical performance and promising application prospects owing to the rich oxygen-containing functional groups, high specific surface and synergistic effect of inorganic additive.

Approaches to the detection of whole cells using reflectometric interference spectroscopy

AbstractMethods for rapid and reliable detection of clinically relevant bacteria are of highest interest. For such purposes, many analytical methods, e.g. ELISA, have been developed. Also optical biosensors like reflectometric interference spectroscopy (RIfS) are suitable analytical platforms. Here, results are described to capture and detect Legionella pneumophila serogroup 1 on differently functionalized surfaces of RIfS glass chips. As a major problem, availability of suitable antibodies was found. Immobilization of capturing antibodies on the chip surface followed by trapping of L. pneumophila gave only insufficient results. For this approach, the chip surface was partially blocked with bovine serum albumin (BSA) in different ratios between BSA and the Legionella specific antibody in order to obtain a site‐directed immobilization. Further on, antibodies were immobilized by hydrophobic interaction followed by BSA treatment and exposition to L. pneumophila. However, also this approach did not allow sufficient capturing of bacteria cells. It can be assumed that binding forces between the antibody and bacteria are too low. Alternatively, L. pneumophila bacteria were directed immobilized on a hydrophobic chip surface. A sufficient sensor signal for quantification was obtained in a range between 8.25 × 106 and 8.25 × 108 bacteria cells/mL. This approach might open up the possibility for safe identification of L. pneumophila after subsequent addition of specific antibodies.

Fetal calf serum enhances in vitro production of Bos taurus indicus embryos

The objective of this study was to determine the effect of fetal calf serum (FCS) on the quality of in vitro produced bovine embryos. Cumulus oocyte-complexes (COCs, n = 2 449) recovered by ovum pick-up from Bos taurus indicus donors were randomly assigned to experimental groups. Sperm selected by Percoll gradient was used for in vitro fertilization (insemination = Day 0). In Experiment 1 (n = 1 745 COCs), zygotes were cultured in vitro in Synthetic Oviduct Fluid + 4 mg/mL of bovine serum albumin (BSA), or BSA + 2% FCS (BSA+FCS). In Experiment 2 (n = 704 COCs), the COCs were cultured in SOF + BSA, BSA + 2% FCS, or BSA + 2% FCS on D4 (BSA + FCSD4). In Experiment 1, blastocyst yield (51%) and Quality I blastocysts (41%) at Day 7 were higher (P < 0.05) in the BSA + FCS treatment than in BSA (42 and 30%, respectively). In Experiment 2, blastocyst yield was higher (P < 0.05) in the BSA+FCS (47%) treatment. Quality I blastocyst yield was higher (P < 0.05) for BSA + FCS (34%) and BSA+FCSD4 (32%) compared to the BSA treatment (20%). A total of 820 embryos were transferred, with no significant differences among groups in pregnancy rates. In conclusion, in vitro culture in SOFaaci + BSA + FCS enhanced blastocyst yield and Quality I blastocysts; adding FCS to the culture medium increased the efficiency of IVP of bovine embryos.

Albumin-bound fatty acids induce mitochondrial oxidant stress and impair antioxidant responses in proximal tubular cells

Albumin induces oxidative stress and cytokine production in proximal tubular cells (PTECs). Albumin-bound fatty acids (FAs) enhance tubulopathic effects of albumin in vivo. We proposed that FA aggravation of albumin-induced oxidative stress in PTECs might be involved. We hypothesized that mitochondria could be a source of such stress. Using a fluorescent probe, we compared reactive oxygen species (ROS) production after exposure of PTECs to bovine serum albumin (BSA) alone or loaded with oleic acid (OA-BSA) (3-30 g/l for 2 h). There was no difference in cellular albumin uptake, but OA-BSA dose-dependently induced more ROS than BSA alone (P<0.001). OA-BSA-induced ROS was significantly alleviated by mitochondrial inhibition, but not by inhibitors of nicotinamide adenine dinucleotide phosphate hydrogenase (NADPH) oxidase, xanthine oxidase, or nitric oxide synthase. Gene expression analysis showed that neither the NADPH oxidase component p22phox nor xanthine oxidase was induced by BSA or OA-BSA. OA-BSA, in contrast to BSA, failed to induce mitochondrial manganese superoxide dismutase 2 (SOD2) expression. OA-BSA showed a greater capacity than BSA to downregulate heme oxygenase-1 mRNA expression and accentuate inflammatory cytokine mRNA and protein. Supplementation of SOD activity with EUK-8 reduced ROS, and interleukin-6 protein expression was suppressed by both mitochondrial inhibition and SOD augmentation. Thus, in PTECs, FAs accentuate albumin-induced oxidative stress and inflammatory cytokine expression via increased mitochondrial ROS, while frustrating protective antioxidant responses.

BSA treatment to enhance enzymatic hydrolysis of cellulose in lignin containing substrates

Cellulase and bovine serum albumin (BSA) were added to Avicel cellulose and solids containing 56% cellulose and 28% lignin from dilute sulfuric acid pretreatment of corn stover. Little BSA was adsorbed on Avicel cellulose, while pretreated corn stover solids adsorbed considerable amounts of this protein. On the other hand, cellulase was highly adsorbed on both substrates. Adding a 1% concentration of BSA to dilute acid pretreated corn stover prior to enzyme addition at 15 FPU/g cellulose enhanced filter paper activity in solution by about a factor of 2 and beta-glucosidase activity in solution by about a factor of 14. Overall, these results suggested that BSA treatment reduced adsorption of cellulase and particularly beta-glucosidase on lignin. Of particular note, BSA treatment of pretreated corn stover solids prior to enzymatic hydrolysis increased 72 h glucose yields from about 82% to about 92% at a cellulase loading of 15 FPU/g cellulose or achieved about the same yield at a loading of 7.5 FPU/g cellulose. Similar improvements were also observed for enzymatic hydrolysis of ammonia fiber explosion (AFEX) pretreated corn stover and Douglas fir treated by SO(2) steam explosion and for simultaneous saccharification and fermentation (SSF) of BSA pretreated corn stover. In addition, BSA treatment prior to hydrolysis reduced the need for beta-glucosidase supplementation of SSF. The results are consistent with non-specific competitive, irreversible adsorption of BSA on lignin and identify promising strategies to reduce enzyme requirements for cellulose hydrolysis.